The dilator naris anterior is a paired, delicate facial muscle that encircles the nostril. It plays a role in widening the nostril, aiding respiration. Some authors consider this muscle to be part of the nasalis muscle.

The size of the dilator naris anterior varies among individuals, and it may even be absent. Along with the alar part of the nasalis muscle, it widens the nostril and may help prevent its collapse during inspiration. Thus, this muscle regulates nostril width in relation to breathing.

Origin: lateral crus of the major alar cartilage; accessory nasal cartilage (if present).

Insertion: integument near the margin of the nostril, skin over the lower margin of the lateral crus of the major alar cartilage.

Action: dilates the nostril, contributing to the widening of the anterior nasal aperture.

Innervation: buccal branch of the facial nerve (CN VII).

Arterial blood supply: lateral nasal branches of the facial artery (a branch of the external carotid artery).

Venous drainage: external nasal veins, which drain into the facial vein (a tributary of the internal jugular vein).

Unlock with Premium

Dilator naris anterior